[depr.static.constexpr] # Annex D (normative) Compatibility features [[depr]](./#depr) ## D.7 Redeclaration of static constexpr data members [depr.static.constexpr] [1](#1) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/future.tex#L148) For compatibility with prior revisions of C++, a constexpr static data member may be redundantly redeclared outside the class with no initializer ([[basic.def]](basic.def "6.2 Declarations and definitions"), [[class.static.data]](class.static.data "11.4.9.3 Static data members"))[.](#1.sentence-1) This usage is deprecated[.](#1.sentence-2) [*Example [1](#example-1)*: struct A {static constexpr int n = 5; // definition (declaration in C++ 2014)}; constexpr int A::n; // redundant declaration (definition in C++ 2014) — *end example*]